A direct-execution framework for fast and accurate simulation of superscalar processors

Multiprocessor system evaluation has traditionally been based on direct-execution based Execution-Driven Simulations (EDS). In such environments, the processor component of the system is not fully modeled. With wide issue superscalar processors being the norm in today's multiprocessor nodes, there is an urgent need for modeling the processor accurately. However, using direct execution to model a superscalar processor has been considered an open problem. Hence, current approaches model the processor by interpreting the application executable. Unfortunately, this approach can be slow. In this paper, we propose a novel direct-execution framework that allows accurate simulation of wide-issue superscalar processors without the need for code interpretation. This is achieved with the aid of an Interface Window between the front-end and the architectural simulator, that buffers the necessary information. This eliminates the need for full-fledged instruction emulation. Overall, this approach enables detailed yet fast EDS of superscalar processors. Finally, we evaluate the framework and show good performance for uni- and multiprocessor configurations.